Dross cooling system and cooling method

ABSTRACT

Embodiments of an aluminum dross cooling head are disclosed. The cooling cooperates with a material container encapsulate dross and reduce thermiting of the dross. In one embodiment, the cooling head also serves as a compression head when forced into the dross by a cooperating dross press assembly.

RELATED APPLICATION DATA

This application is a continuation of U.S. patent application Ser. No.12/784,767, dated May 21, 2010, the disclosure of which is hereinincorporated by reference in its entirety.

FIELD OF THE INVENTION

This invention relates to the cooling of dross and more particularly toa cooling system and cooling method for more effectively coolingaluminum dross resulting from an aluminum recycling process.

BACKGROUND OF THE INVENTION

Dross compression apparatus are commonly used to recover non-ferrousmetals, particularly aluminum, from dross which has been skimmed from afurnace. Aluminum dross is a combination of aluminum metal and aluminumoxides, as well as other possible components such as various oxides,nitrates and carbides. Aluminum dross is a by-product of an aluminummelting operation. Generally the dross floats on top of the moltenaluminum metal in the furnace. Aluminum dross may contain anywhere fromten percent to ninety percent aluminum depending on the particularprocessing technique and the type of furnace. Therefore, the dross in analuminum melting operation includes a significant amount of aluminummetal which is considered a valuable resource to be recovered.

A factor to consider during the cooling of aluminum dross, with orwithout the recovery of aluminum, is thermiting of the dross.Thermiting, or thermite reaction, of the dross is exothermic oxidationof aluminum metal in the dross.

SUMMARY OF THE INVENTION

According to one aspect of the disclosure, a method of cooling aluminumdross includes placing the dross into a receptacle of a materialcontainer; and placing a cooling head on top of the dross so that adownwardly projecting portion of the cooling head engages the dross andlocally deforms the dross under the weight of the cooling head; wherein:the cooling does not include the use of a dross press assembly to exertmechanical force to the dross prior to placing the cooling head on thedross; and the cooling head seals against the material container to atleast partially encapsulate the dross and extinguish oxidation of thedross, and the seal is formed by engagement of an upper rim of thematerial container into a channel of the cooling head.

According to another aspect of the disclosure, a method of coolingaluminum dross includes placing the dross into a receptacle of amaterial container; pressing the dross with a dross press head that ispart of a dross press assembly so that an indentation corresponding to ashape of the dross press head is formed in the dross; and placing acooling head on top of the dross so that a downwardly projecting portionof the cooling head engages the pressed dross; wherein: the cooling headis shaped to make physical and thermal contact with a surface of theindentation in the dross; and the cooling head seals against thematerial container to at least partially encapsulate the dross andextinguish oxidation of the dross, and the seal is formed by engagementof an upper rim of the material container into a channel of the coolinghead.

According to another aspect of the disclosure, an aluminum dross coolinghead for cooling aluminum dross that is placed in a material container,the material container having an upper rim, includes a plate-like upperportion; a protrusion extending downward from the upper portion, theprotrusion configured to make physical and thermal contact with thedross; and a channel circumferentially formed with a perimeter of theupper portion and surrounding the protrusion, the channel configured toreceive the upper rim of the material container during cooling of thedross with the cooling head so that the cooling head and materialcontainer encapsulates the dross and reduces thermiting of the dross byextinguishment.

According to yet another aspect of the disclosure, a method of coolingaluminum dross includes placing the dross into a receptacle of amaterial container; placing the material container containing the drossinto a dross press assembly; placing a compression and cooling head thatis separate from the dross press assembly onto the dross; bringing ahead of a force applicator of the dross press assembly into contact withthe compression and cooling head and compressing the dross by downwardlyforcing the force applicator head against the compression and coolinghead so that the compression and cooling head travels into the dross andinto a seating position in the receptacle, wherein a shape of the forceapplicator head cooperates with a shape of a receiving structure of thecompression and cooling head to allow the compression and cooling headto self align with the dross and material container during compressionof the dross; removing the material receptacle with seated compressionand cooling head from the dross press assembly after compressing; andcooling the dross while the compression and cooling head is in theseated position.

According to still another aspect of the disclosure, an aluminum drosscompression and cooling head for compressing and cooling aluminum drossthat is placed in a material container includes a downward projectionfor engaging the dross; a receiving structure configured to receive acorrespondingly shaped head of a force applicator of a dross pressassembly so that when downward force is applied by the force applicationhead against the receiving structure, the receiving structure cooperateswith the shape of the force applicator head to allow the compression andcooling head to self align with the dross and the material containerduring compression of the dross, the force applicator head and thecompressing and cooling head being separate from each other; and aseating surface for engaging the material container followingcompression of the dross.

According to another aspect of the disclosure, a dross press assemblyfor compressing aluminum dross that is placed in a material containerincludes a force applicator; and a force application head attached tothe force applicator, the head shaped correspondingly with a receivingstructure of a compressing and cooling head so that when downward forceis applied by the force application head against the receivingstructure, the receiving structure cooperates with the shape of theforce applicator head to allow the compression and cooling head to selfalign with the dross and the material container during compression ofthe dross, the force applicator head and the compressing and coolinghead being separate from each other.

These and other features, aspects and advantages of the presentinvention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention,then, comprises the features hereinafter fully described andparticularly pointed out in the claims, the following description andthe annexed drawings setting forth in detail a certain illustrativeembodiment of the invention, this being indicative, however, of but oneof the various ways in which the principles of the invention may beemployed.

BRIEF DESCRIPTION OF THE DRAWINGS

In the annexed drawings:

FIG. 1 is a perspective view of a cooling system in accordance with oneexemplary embodiment of the present invention.

FIG. 2 is a perspective view of a cooling system in accordance withanother exemplary embodiment of the present invention.

FIG. 3 is a perspective view of a multi-chamber cooling system inaccordance with another exemplary embodiment of the present invention.

FIG. 4 is a perspective view of a cooling system in accordance withanother exemplary embodiment of the present invention.

FIG. 5 is a front view of a cooling head in accordance with an exemplaryembodiment of the present invention.

FIG. 6 is a front view of a cooling system in accordance with anexemplary embodiment of the present invention where a skim pot and a sowmold are shown in section.

FIG. 7 is a side view of a cooling head in accordance with anotherexemplary embodiment of the present invention.

FIG. 8 is an oblique view showing a cross-section of a cooling system inaccordance with still another exemplary embodiment of the presentinvention.

FIG. 9A is an oblique view showing a cross-section of a cooling systemin accordance with another exemplary embodiment of the presentinvention.

FIG. 9B is a bottom view of a cooling head that forms part of thecooling system of FIG. 9A.

FIGS. 10 through 15 illustrate various phases of compressing and coolingdross using a cooling system and compression apparatus according toadditional embodiments of the present invention.

FIG. 16 is perspective view of an exemplary cooling head that has beenpressed into a seating position with respect to a material container;

FIG. 17 is a front view of a portion of an exemplary press assembly foruse with the cooling head of FIG. 16;

FIG. 18 is perspective view of another exemplary cooling head that hasbeen pressed into a seating position with respect to a materialcontainer;

FIG. 19 is a front view of a portion of an exemplary press assembly foruse with the cooling head of FIG. 18;

FIG. 20 is a perspective view of another exemplary embodiment of acooling head; and

FIG. 21 is a cross-section of another exemplary embodiment of a coolinghead.

DETAILED DESCRIPTION OF THE INVENTION

Referring now in detail to the drawings wherein like reference numeralsare used to indicate like parts, FIGS. 1 through 7 show variousexemplary embodiments of a cooling system 10. The cooling system 10 maybe used to cool a variety of materials including, for example, aluminumdross, dross from other metal processing, salt cake and so forth. Thematerial may be residue obtained following the recovery of moltenaluminum from a recycling operation or from some other industrialprocess, such as, without limitation, by-products from a magnesiumprocessing system and chloride flux derived from a paper pulp processingsystem. As will be appreciated, these materials are preferably cooledprior to disposal or further processing. The cooling system 10 isarranged to reduce an amount of thermiting that takes place when coolingaluminum dross.

The cooling system 10 includes a cooling head 12. The cooling head 12may be placed on a material container 14. The cooling head 12 andmaterial container 14 have corresponding geometries to cooperate withone another in the manners described herein. Depending on theapplication, the material container 14 may be referred to as a drosscollector, a skim pot, and so forth. The cooling head 12 and/or thematerial container 14 may be made from any appropriate material,including cast alloy steel or grey iron. Grey iron may be cheaper thanalloy steel, but alloy steel may be more resistant to surface checkingand cracking and, as a result, have a longer life-span. Alloy steel alsomay more efficiently cool the material. Alternatively, the cooling head12 and/or the material container 14 may be made from ceramic materials,or may include ceramic components (e.g., a ceramic liner).

The material container 14 may have a receptacle 16 for the material tobe cooled. In the embodiment of FIG. 3, the material container 14 hasplural receptacles 16. In one embodiment, the receptacle 16 and/or aportion of the cooling head 12 that projects into the receptacle 16 maybe substantially hemispheric shaped. Of course, other shapes arepossible.

In some configurations, the material container 14 may be provided withone or more openings 18 (best shown in FIG. 6) at the bottom of thereceptacle 16 to allow molten aluminum (or other flowable material) topass by gravity and/or under the pressure from the cooling head 12. Thesubstance passing through the openings 18 may be collected in acollector pan 20 disposed under the material container 14. Depending onthe industrial application, the collector pan 20 may be referred to as adrain pan or a sow mold.

The material container 14 and/or the collector pan 20 may includepassages 22 that accept forks of a forklift truck for transporting thematerial container 14 and/or collector pan 20. In one embodiment, thecooling head 12 may include tubular members 24 for receipt of the forksof a forklift truck for transporting the cooling head 12 and/orpositioning the cooling head 12 on the material container 14. In anotherembodiment, the cooling head 12 may be wider than the material container14 and the forks of the forklift truck may move and/or position thecooling head 12 by engaging portions of the cooling head 12 thatoverhang the material container 14. In yet other embodiments, thecooling head 12 may be moved and/or positioned with respect to thematerial container 14 using a hoist or crane. The cooling head 12 mayinclude a hook(s), ring(s) or other member for facilitating coupling ofthe cooling head 12 to the hoist or crane by way of, for example, arigid member, a cable, a chain, a hook, and so forth. In one embodiment,such as the embodiment shown in FIG. 4, the cooling head 12 may becoupled to a lever arm 26. The lever arm 26 may be raised and lowered(and possibly swung) to position the cooling head 12 with respect to thematerial container 14. In the illustrated embodiment, the elevation ofthe lever arm 26 is controlled by a hydraulic piston 28, but othermechanisms for positioning the lever arm 26 are possible. The lever arm26 may connect directly to the cooling head 12 or may connect to thecooling head 12 by way of a rigid member, a cable, a chain, a hook, aball joint, a spring and/or some other member. The lever arm 26 may bemounted to a stationary frame.

The cooling head 12 may have a downwardly projecting protrusion 30. Asillustrated, a plate-like member that forms an upper portion 32 of thecooling head 12 has a depression, or well, that forms the protrusion 30by protruding downwardly for making thermal contact with the material.The upper surface of the upper portion 32 may be depressed so that thelower surface of the protrusion 30 is convexly curved and is disposedbelow the surrounding flange-like members formed by the upper portion32. In some embodiments, the protrusion 30 may be substantiallyhemispheric shaped. When the cooling head 12 is positioned on thematerial container 14, the protrusion 30 may enter the receptacle 16through an open top of the material container 14 and the protrusion 30may contact the material contained in the material container 14. Thecooling head 12 may include multiple protrusions 30, such as aprotrusion 30 for each receptacle 16 of a multi-receptacle 16 materialcontainer 14 (e.g., the cooling head 12 and the material container 14 ofFIG. 3).

Heat from material contained in the material container 14 may betransferred to the protrusion 30. A substantial amount of thetransferred heat may be conveyed to the upper portion 32 of the coolinghead 12. In one embodiment, the upper portion 32 of the cooling head 12may be a plate that surrounds the protrusion 30. In the illustratedembodiments, the upper portion 32 is open so that a recess formed by theprotrusion 30 is open to the environment. This open recess, or well,creates surface area for efficient heat transfer and provides a lightercooling head 12 relative to a cooling head 12 that has a solidprotrusion 30 or a covered protrusion 30. The surface of the well (whichis the upper surface of the protrusion 30) may be relatively smooth asshown or have structural elements (e.g., ribs).

The lower surface of the protrusion 30 may be relatively smooth as shownin FIGS. 1 through 4. Alternatively, the lower surface of the protrusion30 may have structural elements, such as ribs 34 as shown in FIGS. 5-7.As used herein, the term rib means any projection or shape which forms aprojection, raised area, ridge, corner or non-continuity on a surface.Ribs also may be referred to as fins or flanges. The ribs 34 may extendinto the material in the material container 14 to help dissipate and/ortransfer the heat in the material. Also, such ribs may help increase thecompressive force on the material. In the exemplary embodiments of FIGS.1-7, the cooling head 12 is placed on the material container 14 and anycompression of the material in the material container 14 is achievedsolely by the weight of the cooling head 12 acting on the material. Inother embodiments, downward force may be applied to the cooling head 12to achieve compression of the material. Such downward force may beapplied, for example, using a press assembly, as described in greaterdetail below. In other embodiments, downward force may be applied by aforklift truck or the lever arm 26 used to move the cooling head 12.

To assist in dissipating and/or radiating heat from the material to theenvironment, the cooling head 12 may include structural elements on theupper surface of the upper portion 32. For instance a series of ribs 36may be present. The tubular member 24, if present, also may serve toassist in dissipating and/or radiating heat. In effect, the ribs 36and/or other elements on the top of the cooling head 12 may help toremove heat from the cooling head 12. To enhance the removal of heatfrom the cooling head 12, cooling air may be directed across the top ofthe cooling head 12. For instance, as shown in FIG. 2, a blower 38 orother ventilation system may draw air across the top of the cooling head12 as graphically portrayed by arrow 40. In other embodiments, the airmay be blown across the top of the cooling head 12. Plural coolingsystems 10 may be arranged in close proximity to each other such thatair may be directed across multiple cooling heads 12 to assist incooling material that is dispensed into multiple corresponding materialcontainers 14.

The ribs 36 on the cooling head 12 may extend generally in the samedirection, such as from the front of the cooling head 12 toward the backof the cooling head 12 (e.g., as shown in FIGS. 1-2 and 4-7) or from oneside to another side (e.g., as shown in FIG. 3). The directionality ofthe ribs may help channel cooling air that is directed across the top ofthe cooling head 12. For instance, cooling air may be directed along thepeaks 42 and valleys 44 of the ribs 36 as best illustrated in FIGS. 5and 6. Any suitable nozzle assembly, blower, manifold, fan or aircirculator may be used to create an air flow to assist in removing heatfrom the cooling head 12.

A lower surface of upper portion 32 may be configured to engage an upperedge of material container 14. The interface (or closure) between thecooling head 12 and material container 14 may reduce the flow of gassesinto the receptacle and reduce oxidation of the material in the materialcontainer 14 during cooling. As indicated, edge portions of the upperportion 32 may overhang the material container 14. Overhanging portions46 may be bent downward to enhance the sealing effect, to divert airflow and/or to provide a lip to assist in stabilizing the cooling head12 in embodiments where a forklift is used to lift the underside of thecooling head 12. Downwardly bending and overhanging portions 46 may bepresent on any combination of the front edge, the rear edge, the leftside edge and the right side edge.

The well formed by the protrusion 30 may be filled with a material toassist in weighting the cooling head 12 and/or adjusting the coolingbehavior of the cooling head 12. For instance, sand, metal shot, platesor a conforming metal insert may be placed in the well. Also, a coolingapparatus may be placed in the well. In other embodiments a coolant (inaddition to or instead of the above-described air) may be directedacross the surface of the recess and/or the ribs 36. For instance, wateror oil may be circulated with respect to the cooling head 12.

In another embodiment, a vibrator may be placed in the well or on top ofthe cooling head 12. The vibrator may be activated to shake the coolinghead 12 to assist in compaction of dross and promote the draining ofmetal into the collector pan 20.

In an exemplary industrial application to process aluminum dross, acompression apparatus with integrated compression head may be used tocompress dross in a time period of about an hour or less. An exemplarycompression machine for this purpose is disclosed in, for example, U.S.Pat. No. 5,397,104, the disclosure of which is incorporated herein byreference in its entirety. Then, the container in which the dross wascompressed may be moved from the compression apparatus and a coolinghead (e.g., the cooling head 12) may be placed on the moved dross anddross container to further cool the dross for a period of time, such asabout one hour to about two hours. This allows for increased use of thecompression apparatus for compression, which leads to increasedthroughput and process efficiencies.

With additional reference to FIG. 8, shown is another embodiment of thecooling system 10. Similar to the foregoing cooling systems 10, thecooling system 10 of FIG. 8 includes a cooling head 12, a materialcontainer 14, and a collection pan 20. Features that the cooling system10 of FIG. 8 has in common with the foregoing cooling systems 10 willnot be described in detail.

The cooling head 12 of FIG. 8 includes a generally planar plate thatforms the upper portion 32. The upper portion 32 does not have adepression or well that forms the protrusion. Rather, the cooling headhas a downward protrusion 48 that projects from a lower side of theupper portion 32. The protrusion 48, which is preferably solid, makesthermal contact with the dross. In addition, and similar to theabove-described cooling heads 12, the cooling head 12 may include ribs36 and tubular members 24 that extend upward from an upper side of theupper portion 32. Since a well is not present in the cooling head 12,the ribs 34 may traverse a central portion of the cooling head 12.

Engagement of the cooling head 12 of FIG. 8 against an upper rim 50 ofthe material container 14 may form a seal and may serve to encapsulatethe dross in a volume formed by the material container 14 and coolinghead 12. The encapsulation and sealing may reduce fume release anddusting. The cooling head 12 may be structurally arranged to form theseal. For example, in the illustrated embodiment, the lower side of theupper portion 32 may include a channel 52 around the perimeter of thecooling head 12 into which the rim 50 is received. In one embodiment,the channel 52 is formed by making the upper portion 32 in the area ofthe channel 52 thinner than the upper portion 32 located inside thechannel 52. In addition, the cooling head 12 may be larger than thematerial container 14 in the lengthwise and widthwise directions so thatthe upper portion 32 overhangs the material container 14 withoverhanging portions 46. The overhanging portions 46 may be bentdownward to establish the channel 52 between the overhanging portions 46and the thicker portion of the upper portion 32. In the embodiment ofFIG. 8, the overhanging portions 46 are bent downward at an angle ofabout 45 degrees. This angle may be less than or greater than 45degrees. For example, with additional reference to FIG. 21, a coolinghead 12 is shown with overhanging portions that are bent downward atangle of about 90 degrees.

To enhancing sealing of the cooling head 12 with the rim 50, a sealingmaterial may be placed between the rim 50 and the head 12. For example,in the embodiment of FIG. 21, a sealing member 80 is retained in thechannel 52. The sealing member 80 may alternatively be retained by thematerial container 14, or placed on the material container 14 prior topositioning of the cooling head 12 to cover the material container 14.The sealing member 80 may be made of ceramic material, such as ceramicrope or a ceramic fiber mat, and may deform slightly between the head 12and container 14. The sealing member 80 is shown in FIG. 21 as beingrectangular. It will be appreciated that other shapes are possible.

The cooling head 12 of FIG. 8 is intended for use when dross is placedin the material container 14, but is not pressed with a dross pressassembly. Rather, the cooling head 12 is placed on the materialcontainer 14 and unpressed dross. The protrusion 48 may be sized to havea penetration height and/or penetration volume that is smaller than thepenetration height and/or penetration volume of a press head from aconventional dross press assembly. In this embodiment, the cooling head10 may be used as a “dead” weight that is positioned, and possiblyforced downward into the dross, with a fork truck. The cooling head 10may serve to enhance dross cooling, reduce thermiting and/or oxidizingof the aluminum in the dross (by removing heat and by encapsulation tolimit oxygen supply), promote aluminum draining into the collection pan20, and reduce fume release and dusting.

Turning now to FIGS. 9A and 9B, shown is another embodiment of thecooling system 10. Similar to the foregoing cooling systems 10, thecooling system 10 of FIGS. 9A and 9B includes a cooling head 12, amaterial container 14, and a collection pan 20. Features that thecooling system 10 of FIGS. 9A and 9B has in common with the foregoingcooling systems 10 will not be described in detail.

Similar to the cooling head 12 of FIG. 8, the cooling head 12 of FIGS.9A and 9B includes a generally planar plate that forms the upper portion32. The upper portion 32 does not have a depression or well that formsthe protrusion. Rather, the cooling head has a downward protrusion 48that projects from a lower side of the upper portion. The protrusion 48,which is preferably solid, makes thermal contact with the material. Inaddition, and similar to the above-described cooling heads 12, thecooling head 12 may include ribs 36 and tubular members 24 that extendupward from an upper side of the upper portion 32. Since a well is notpresent in the cooling head 12, the ribs 34 may traverse a centralportion of the cooling head 12.

Engagement of the cooling head 12 of FIGS. 9A and 9B against an upperrim 50 of the material container 14 may form a seal and may serve toencapsulate the dross in a volume formed by the material container 14and cooling head 12. The encapsulation and sealing may reduce fumerelease and dusting. The cooling head 12 may be structurally arranged toform the seal. For example, in the illustrated embodiment, the lowerside of the upper portion 32 may include a channel 52 around theperimeter of the cooling head 12 into which the rim 50 is received. Thecooling head 12 may be larger than the material container 14 in thelengthwise and widthwise directions so that the upper portion 32overhangs the material container 14 with overhanging portions 46. Theoverhanging portions 46 may be bent downward to establish the channel 52to the inside of the overhanging portions 46, such as between theoverhanging portions 46 and a thicker portion of the plate-like upperportion 32 in similar manner to the embodiment of FIG. 8.

The cooling head 12 may include legs 56 to allow stacking of pluralcooling heads 12 upon one another when not in use. In one embodiment,the legs 56 are formed separately from the cooling head 12 and may slideover receiving lugs 58 of the cooling head 12. Alternatively, the legsmay be cast or otherwise integrally formed with the cooling head 12 soas to form a monolithic structure, such as in the exemplary embodimentof FIG. 20. When stacked, lower ends of the legs 56 may rest onrespective upper surfaces of the lugs 58 (or an upper surface of theupper portion 32) of an underlying cooling head 12.

In one embodiment, the cooling head 12 of FIGS. 9A and 9B is intendedfor use when dross is placed in the material container 14, and thenpressed with a dross press assembly. After the dross is pressed, thecooling head 12 is placed on the material container 14 and presseddross. The protrusion 48 may be sized to have a penetration heightand/or penetration volume that is the same as or approximately the sameas the penetration height and/or penetration volume of a press head froma dross press assembly. The configuration of the under side of thecooling head 12 is preferably arranged to closely fill the indentationformed in the dross by the press assembly. In this manner, thermalcontact may be made between the dross and the cooling head 12, but thecooling head 10 may be used as a “dead” weight that is positioned with afork truck. The cooling head 10 may serve to enhance dross cooling,reduce thermiting and/or oxidizing of the aluminum in the dross (byremoving heat and by encapsulation to limit oxygen supply), promotealuminum draining into the collection pan 20, and reduce fume releaseand dusting.

In one embodiment, the cooling head may include supplemental projections54 that are configured to make contact with and embed themselves intoloose dross material that may be present after pressing.

With additional reference to FIGS. 10 through 15, illustrated arevarious phases of compressing and cooling hot aluminum dross using acooling and compression system. The illustrated system shows thesimultaneous compression and cooling of two containers 14 of aluminumdross 60. It will be appreciated that the below described apparatus andmethods may apply to compressing and cooling one container 14 of dross60 (or other material) at one time, or compressing and cooling more thantwo containers 14 of dross 60 (or other material) at one time. Also,features of the cooling and compression system that are common with theforegoing cooling systems 10 will not be described in detail.

The system uses a cooling head as a press head. This head is notpermanently affixed in a press assembly. That is, the head is separatefrom the press assembly and, although the head interacts with the pressassembly during pressing, the head is not mechanically connected to,affixed or attached to, touching and/or in direct contact with the pressassembly prior to pressing or after pressing. When compression iscompleted, the dross container is removed from the compression assemblywith the head in place as a cover to the container. The container andhead may be set aside for further cooling. The head and the cooled drossmay be removed from the container, after which the head and containermay be reused.

In a conventional compression system, after compression, the compressionhead is brought out of contact with the compressed dross and thecontainer is removed from the compression assembly. At this time, thedross is exposed to the atmosphere through the open top of the drosscontainer. The system of FIGS. 10-15 leaves the head in place over thedross after compression. Therefore, less exposure of the dross to theatmosphere occurs and, as a result, less thermiting of the dross mayoccur after compression. In addition, the head and dross will be inclose conformity with one another following the compression phase sincethe head itself is used to compress the dross.

In FIG. 10, a first phase of compressing and cooling dross isillustrated. In this phase, hot aluminum dross 60 is skimmed into thematerial containers 14. In the illustrated embodiment, the containers 14are a set of dross pans. The dross pans may be integral with one anotheror separate units. The containers 14 may be placed upon respectivereceptacles 16. In the illustrated embodiment, the receptacles 16 forthe two containers 14 are integrally formed to form a unitary drain pan62 (also referred to as a sow mold). Also, the containers 14 may besecured to the drain pan 62 with latching devices 64. The containers 14and drain pan 62 will be collectively referred to as a dross pan set 66.The containers 14 and drain pan 62 may be made from cast alloy steel,grey iron or a ceramic material, and may be configured to optimizecooling of the dross and aluminum recovered through draining into thedrain pan 62.

In FIG. 11, a second stage of compressing and cooling dross isillustrated. In this phase, a dross press door (not shown) of a pressassembly 68 may be opened. A forklift truck may be used to position thedrain pan set 66 into the press assembly 68.

In FIG. 12, a third stage of compressing and cooling dross isillustrated. In this phase, a compression and cooling head 70 is placedon the dross in each container 14. The head 70 may include a protrusion30 that is forced into the dross 60 by pressing action of the drosspress assembly 68 (discussed below). In the illustrated embodiment, theprotrusion 30 includes ribs 34.

With additional reference to FIG. 15, each head 70 may be shaped tocorrespond to the shape of the container 14. In one embodiment,following pressing, a perimeter edge of the head 70 may seat itselfslightly into the dross receptacle 16 of the container 14. In theillustrated embodiment, the perimeter edge of the head 70 may beconsidered a seating surface. The seating surface may be arranged inother manners. For instance, the seating surface may be a rib or otherprojection that inscribes the protrusion 30, or may be a channel similarto the channel 52 of the heads 12 illustrated in FIGS. 8 and 9. Eachhead 70 may include tubular members 24 to allow movement by a forklifttruck. Also, the tubular members 24 may serve to assist in dissipatingheat. Although the illustrated heads 70 do not include cooling ribs onan upper surface of the head 70, ribs may be present. The head 70 may bemade from cast alloy steel, grey iron or a ceramic material.

A hemispherical well 72 may be present in the center of the uppersurface of the head 70. The well 72 may be surrounded by a ridge 74. Thewell 72 is shaped to cooperate with a head 76 of a hydraulic orpneumatic cylinder 78 (or other force applicator, e.g., screw assembly)of the press assembly 68. For example, the head 76 may be hemispherical.As used herein for the well 72 and the head 76, the term hemisphericalincludes shapes that are a segment of a sphere (e.g., less than or morethan exactly one half of a sphere); a spherical sector (or sphericalcone); any other conoid or portion thereof, including spheres,ellipsoids, oblate spheroids, prolate spheroids, and catenoids; apyramid but with a substantially rounded end (e.g., akin to thewell/protrusion of the head 10 shown in FIGS. 1-4); and so forth.

In this manner, the head 70 need not be placed level on the dross 60.For instance, the left-hand head 70 in FIG. 12 is placed slightly askewon the dross 60. As the head 76 and cylinder 78 are used to force thehead 70 downward into the dross 60 by pressing the head 76 into the well72, the head 70 will self align and seat itself with respect to thecontainer 14. During this action, and due to the cooperating shapes ofthe well 72 and head 76, pivoting of the head 70 may occur with respectto the head 76.

The head 70 is configured to squeeze the dross 60 to push moltenaluminum contained in the dross 60 through the openings 18 in the bottomof the receptacle 16 and into the collection pan 20. The head 70 isfurther configured to simultaneously cool the dross 60 and encapsulatethe dross 60 to extinguish any thermiting material in the dross 60.

Continuing to refer to FIG. 12, once the head 70 is positioned on thedross 60, the door of the dross press assembly 68 may be closed. Asindicated, the door is not shown in the attached figures. Omitting thedoor for purposes of this document facilitates visualization of theoperation of the cooling and compression system.

In FIG. 13, a fourth stage of compressing and cooling dross isillustrated. In this phase, the cylinders 78 force the heads 76 intocontact with the respective heads 70 that, in turn, are forced into thedross 60. As indicated, this action results in forcing aluminum throughthe openings 18 and into the collector pan 20. Also, this action resultsin forcing aluminum to the outside of the dross 60 and against the wallsof the receptacle 16 and protrusion 30. This aluminum forms a metallic“skin” around the dross, which aids in blocking air contact with thedross and further reduces oxidation of the dross.

In FIG. 14, a fifth stage of compressing and cooling dross isillustrated. When the pressing stage is completed, the cylinders 78 andaccompanying heads 76 may be retracted. In one embodiment, pressing maybe considered complete when maximum compression of the dross 60 isachieved and the head 70 becomes seated in the receptacle 16. When thecylinders 78 are fully retracted, the door of the dross press assembly68 may be opened.

Then, as illustrated in FIG. 15, the dross pan set 66 with heads 70 maybe removed from the dross press assembly 68 for further cooling. Afterremoval of the dross pan set 66 from the dross press assembly 68, thepressing steps may be repeated with a different dross pan set 66 andheads 70.

In one embodiment, the further cooling is achieved by allowing the drosspan set 66 with heads 70 in place to stand. In addition, cooling air maybe directed at the dross pan set 66. In still other embodiments, acooling assembly may be brought into contact with the head 70. Forinstance, a liquid-based (e.g., water or oil) heat exchanger may beinserted into the well 72.

Once the compressed dross 60 is sufficiently cooled, the heads 70 may beremoved using a forklift truck. Then, the material containers 14 may beremoved from the drain pan 62 and inverted to remove the cooled dross60. Next, the drain pan 62 may be inverted to remove any recoveredaluminum. The components may be reused to process additional dross.

With additional reference to FIG. 16, another head 70 embodiment isshown. In this embodiment, the head 70 is elongated so that the width ofthe head is greater than the depth of the head 70. The head 70 has apair of spaced apart wells 72 for receiving respective compression heads76. In the illustrated embodiment, a protrusion 30 is disposed betweenthe wells 72. The protrusion 30 may be solid or, as illustrated, form anaccompanying well.

Similar to the embodiments of FIGS. 10-15, the head 70 of FIG. 16 may beforced with the cylinders 78 and heads 76 into a seating position withrespect to a container 14 so that a perimeter edge of the head 70 isseated into the dross receptacle 16 of the container 14. With additionalreference to FIG. 17, rods of the pair of cylinders 78 and/or the pairof heads 76 may be connected with a coupling member 82. The couplingmember 82 may be configured to dissipate force across the top of thehead 70. The coupling member 82 may be configured to contact the top ofthe head 70 during compression or may be configured to be spaced apartfrom the head 70 during compression.

FIG. 18 illustrates another elongated head 70 that is configured to bepressed into a seating position with respect to a container 14 so that aperimeter edge of the head 70 is seated into the dross receptacle 16 ofthe container 14. In the embodiment of FIG. 18, the head 70 has a singlewell 72, which may be elongated as shown in the illustrated embodiment.The head 70 of FIG. 18 may be pressed into the container 14 with asingle cylinder 78 and head 76 or with a pair of cylinders 78 and heads76 (e.g., with the apparatus of FIG. 17). In the case where the head 70is pressed with a pair of cylinders 78 and heads 76, the pair ofcylinders 78 and/or the pair of heads 76 may be connected with thecoupling member 82. In another embodiment, and as shown in FIG. 19, apair of cylinders 78 may act upon a monolithic head 76 that is shaped tooperatively interact with the well 72. It will be appreciated that themonolithic head 76 of FIG. 19 may be modified so as to interact withplural wells 72, such as the wells 72 in the embodiment of FIG. 16.

With additional reference to FIG. 20, the head 12 or 70 may include ahollow passage 84 through which a cooling fluid, such as air, iscirculated. The passage 84 may be connected to an inlet 86 and an outlet88. Pipes or flexible hoses may be attached to the inlet 86 and output88 to act as a source of the cooling fluid and as an exhaust for thecooling fluid, respectively. In one embodiment, a header assembly thatforms part of a cooling station may supply and exhaust cooling fluid toplural heads 12 or 70.

With additional reference to FIG. 21, inert gas (e.g., argon ornitrogen) may be injected into spaces between the dross and head 12 or70. In one embodiment, holes 90 may be formed in the head 12 or 70 andsupply hoses may be connected to the holes 90 to deliver the gas. In oneembodiment, the holes 90 may be threaded to receive mating couplers ofthe hoses, or plugged in the event that inert gas is not used. The inertgas may assist in extinguishing any thermiting or burning of aluminum inthe dross. In this embodiment, the head 12 or 70 is used as a cover toretain the inert gas with respect to the dross. In addition, the head 12or 70 makes physical and thermal contact with the dross to remove heatfrom the dross by conduction. Also, the head 12 or 70 may compress ordeform the dross.

Although the invention has been shown and described with respect tocertain embodiments, equivalent alterations and modifications will occurto others skilled in the art upon the reading and understanding of thespecification. In particular, with regard to the various functionsperformed by the above described components, the terms (including anyreference to a “means”) used to describe such components are intended tocorrespond, unless otherwise indicated, to any component that performsthe specified function of the described component (e.g., that isfunctionally equivalent), even though not structurally equivalent to thedisclosed component which performs the function in the hereinillustrated exemplary embodiments of the invention. Also, control of allof the disclosed functions may be computerized and automated as desired.In addition, while a particular feature of the invention may have beendisclosed with respect to only one embodiment, such feature may becombined with one or more other features as may be desired andadvantageous for any given or particular application.

1. A method of cooling aluminum dross, comprising: placing the drossinto a receptacle of a material container; and placing a cooling head ontop of the dross so that a downwardly projecting portion of the coolinghead engages the dross and locally deforms the dross under the weight ofthe cooling head; wherein: the cooling does not include the use of adross press assembly to exert mechanical force to the dross prior toplacing the cooling head on the dross; and the cooling head sealsagainst the material container to at least partially encapsulate thedross and extinguish oxidation of the dross, and the seal is formed byengagement of an upper rim of the material container into a channel ofthe cooling head.
 2. The method of claim 1, wherein heat from the drossis radiated from a plurality of ribs located on top of the cooling headto reduce thermiting of the dross.
 3. The method of claim 2, furthercomprising directing cooling air across the top of the cooling head andbetween the ribs to cool the cooling head.
 4. The method of claim 1,wherein the downward projection is formed by a well in an upper portionof the cooling head.
 5. The method of claim 1, wherein the downwardprojection is solid and an upper portion of the cooling head is a solidplanar plate.
 6. The method of claim 1, wherein the channel is formedoutside the upper rim of the material container by downwardly projectingportions of the head that overhang the material container.
 7. The methodof claim 1, wherein the channel is formed inside the upper rim of thematerial container by a rib that projects downward from an upper portionof the cooling head.
 8. The method of claim 1, wherein the cooling headis placed into position on the dross with a forklift truck and theforklift truck is used to apply downward pressure of the cooling headagainst the dross.
 9. The method of claim 1, wherein the downwardlyprojecting portion includes ribs on a lower surface thereof.
 10. Themethod of claim 1, wherein the cooling head is lowered into contact withthe material with a lever arm.
 11. The method of claim 1, furthercomprising collecting a liquid component of the material that drainsthrough holes of the material container with a collector pan.
 12. Themethod of claim 1, further comprising vibrating the cooling head duringdeformation of the dross.